THE INDIAN SCHOOL, AL GHUBRA
DEPARTMENT OF CHEMISTRY
CLASS 1 I
WORKSHEET - ATOMIC STRUCTURE
1
Define the terms (i) atomic number and ( i i ) mass number.
2
What is electromagnetic spectrum ?
3
Write a short note on Planck's quantum theory.
4
How is spectrum of hydrogen obtained?
5
What is the value of Rydberg constant?
6
What is the total number of orbital associated w i t h n = 3 Using s, p, d, f notation
describe the orbital with following quantum numbers- :
n=2 l=1 ,
n=4 1=0,
n=3 l=2
7
Give main achievements of Bohr's model of atom.
8
Explain spectrum of hydrogen on the basis of Bohr's model of atom
c
)
Account for stability of atom with the help of Bohr's theory.
10
State and explain Heisenberg's Uncertainty principle.
11
What is meant by dual nature of matter ? Derive de Broglie equation
12
What do you understand by quantum numbers ? What information are conveyed by
(i)principal, (ii) azimuthal, iii) magnetic (iv) spin quantum number ?
13
State (n +1 ) rule. Illustrate it with the help of example. Give the sequence of
tilling orbital using (n +1 ) rule.
14
Which of the following are isoelectronic species, i.e., those having the same number
of electrons ? Na+, K + , Mg2+, Ca2+ , S2- .
15
(i) Write the electronic configurations of the following ions : (a) H+
(b) Na+ (c) O 2- (d) F- .
(ii) What atoms are indicated by the following configurations, a)[He]2s 1
(b) [Ne] 3s2 c) [A r]4s 2 3d 1 .
16
What is the lowest value of n that allows g orbitals to exist ?
17
An electron is in one of the 3d orbitals. Give the possible values of n, l and m for this
electron.
18
Give the number of electrons in the species H 2, H2+, O2+
19
(i) An atomic orbital has n= 3. What are the possible values of l and
m?
(ii) List the quantum numbers (n, l and m) of electrons for 3d orbital.
20
The Vividh Bharti Station of A.I. Radio broadcasts on a frequency of 1,368
kHz (kilohertz). Calculate the wavelength of the electromagnetic radiation
emitted by transmitter. Which part of electromagnetic spectrum does it
belong to ?
21
The wavelength of visible spectrum extends from violet 400 nm to 750 nm. Express
the wavelength in frequencies (Hz).
22
Calculate (a) wave number and (b) frequency of yellow radiation
with wavelength 5800 A°.
23
Calculate the energy of one mole of photons whose frequency is 5 X 10 14 Hz.
24
A 100 Watt bulb emits monochromatic light of wavelength 400 nm. Calculate
the number of photons emitted per second by the bulb.
25
The threshold frequency for a metal is 7.0 x 10 1 4 s-1. Calculate the kinetic energy of
an electron emitted when radiation of frequency 1 X 10 15s-1 hits the metal.
26
27
28
29
30
31
32
33
34
35.
Calculate the energy associated with the first orbit of He+. What is the radius of this
orbit?
The mass of an electron is 9.1 x 10-31kg. If its K.E is 3.0 X 10-25 J. Calculate its
wavelength. What part of electromagnetic spectrum does it belong to ?
Calculate the wavelength of the spectral line when the electron in the hydrogen atom
undergo transition from 4th energy level to second energy level.
When radiation of wavelength 300 nm falls on surface of sodium, electrons are emitted
with a kinetic energy of 1.68 x 105 J mol'. What is the minimum energy needed to
remove an electron from sodium ? What is the maximum wavelength that will cause a
photoelectron to be emitted ?
What are the frequency and wavelength of a photon emitted during a transition from the
n1=5 state to n2= 2 state in the hydrogen atom ?
A photon of wavelength 4 x 10-7 m strikes on metal surface, the work function of the
metal being 2.13 eV. Calculate (i) the energy of the photon (eV) ij) the kinetic energy of
the emission and iii)j the velocity of the photoelectron. (I eV = 1.6020 x 10 -19j).
What is the maximum number of emission lines when the excited electron of a H atom in
n = 6 drops to the ground state ?
(i) The energy associated with the first orbit in the Hydrogen atom is - 2.17 x 10-18 J/atom.
What is the energy associated with the fifth orbit ?
(ii) Calculate the radius of Bohr's fifth orbit for hydrogen atom.
The electron energy in hydrogen atom is given by E=- 2.17 x 10-18/n 2 joules. Calculate
the energy required to remove an electron completely from the n= 2 orbit. What is the
longest wave length in cm of light that can be used to cause this transition ?
Calculate the wavelength of an electron moving with a velocity of 2.05 x 107m/s